The present invention relates generally to a gear tester used for testing the quality of meshing between mating gears, and more particularly, to a gear tester method and apparatus for inspecting the contact area between mating gears under different mounting positions of the gears while the gears are rotating.
In the prior art, it has long been the practice to visually inspect the shape, size and orientation of the contact area between the mating teeth of two gears, for example a gear member and a pinion, by driving the gear member with the pinion (usually under light load) with the gear tooth surfaces covered with a thin layer of paint. As the paint is removed from portions of each gear tooth surface due to contact from a corresponding tooth of the pinion, a "footprint" of the contact region remains visible on the contacting tooth surface of the gear member.
The main problem associated with this process is that in order to observe the footprint, the gear tester had to be stopped and visually inspected every time a new mounting position between the gear member and pinion was used. Since the gear tester had to be stopped, it became customary either to remove the old paint from the teeth surfaces by rubbing the gear member clean or to respray the teeth surfaces. The pinion or gear member mounting position would then be changed to obtain a new set of footprints. The constant stopping, inspecting and respraying process added substantial time to the testing runs. In addition, a detailed record of the test results for each run was difficult to maintain.